Yes, A rabbit bit with a bearing would work, but I want to open up the rabbited area from the current 1/4" rabbit cut to a 1/2" cut. This will give me a wider area to use for screwing down a metal ring that I want to glue to the passive assembly(thus making the whole thig removable). I figure that if I use #6 flathead machine screws I will need the ring to be around 1/2" to allow for the countersunk holes. Also I need the additional room for the tee-nuts on the inside of the cabinet.

What I would need is a bearng bit that will cut a 1/2" wide rabbit cut. Do they make that size? My company's shop doesn't have one, but I would spring for one if it can be bought for under $35.

I've used the cheap chinese router bits. I think they're fine for garage weekend warrior types like many DIY speaker builders. Of course they won't last if you're a pro or frequent user, but then again you can buy new bits for the price of having good ones sharpened.

I am building my HDTs right now. I am incorporating the MK I alternate tuning. I have the information about the egg crate foam pieces as described in the kit docs. Does it make any sense to do more foam in the chambers than the kit mentions? Since I have the units fully accessible to the internal chambers, now would be a good time to know this.

Or are there any other treatments I should consider before sealing them up for 'eternity' ?

I wouldn't add any other foam other than whats on the paper, we tried everything we could think of last winter and thats where Steve thought it to be the best. In my opinion, for the Fostex driver, the Alt tunning can't be beat, except by adding the gell coated driver which is just putting icing on the cake.

On the other hand the HDT MKII has nothing in the cabinet. It doesn't need anything which is how the originial was when Steve first designed it. It only took 6 years for the first one.

I was admiring my alternate tuned passives in the sunlight today and am amazed at how responsive they are to light touch. With no music playing, just very gently brushing one with an absolute minor touch causes the other one to respond immediately. Tapping one causes the other to jump with a large amount of excursion. You need to have a bright light or sunlight shining on the one you are looking at to see just how responsive this is. I don't know if these have broken in more but I am amased how quick and how light a tap is "mirrored."

Completed the Alternate tuning kit and gelled driver upgrade last week. Thanks Bob, Steve and Devon for all your help in rectifying the shipping damage that unfortunately occured. I appreciate your quick efforts to resolve, and Bob I appreciated all the kind help you provided me to walk thro the mods. (I finally coaxed the fostex drivers out of their tacky home!!)

This mod definitely improves the speakers tonal balance, improves bass speed and articulation, the speakers do disappear more and soundstaging is better (I heard something outside my right speaker yesterday, that was cool).

The mod is fresh, so difficult to provide any full reports, but important to note that the above listening was done with a solid state belles amp and adcom pre. I had not enjoyed this combo with the stock HDT's for the last 2 months I've had them together. The fact is that the newly modded HDT's sound better than I ever expected them to with this SS combination (much more listenable and smooth than they did prior to upgrade).

I'm waiting for a new tube amp to arrive in the next few weeks, and I've bought some NOS bugle boys, mullards, and some cool rectifiers tubes to roll.

I originally had the stock HDT's with a Select and loved female vocals, loved its speed, but felt rock lacked bass foundation. I added an expensive / fast sub and it sounded pretty good.

Steve recommended the EX mod, which I completed and it did help the bass, however (as Steve said it would) it removed some of the air in the top end, and that was some magic I hated to lose.

Following the EX mod (and as the drivers burned in), I felt I started to enjoy the HDT's better without sub, so I began to run them more on their own.

I had plans to upgrade to Steve's new Torii Mk2 in anticipation of potentially increasing the choices of speaker models that I could audition and own, and I sold the EX to ready myself for the upgrade. At about the same time, however, the HDT Alternate tuning kit came out, so I decided to do that first to see if I had really heard the full potential of the HDT's, and am glad I did.

I had the Belles and Adcom on hand so have been using them in the interim, and again, am surprised how listenable (after such a short period of breakin) the system has become.

I will try to post again after new amp, new tubes, and some burnin has occured.